Steering-gear for motor-boats



J. E. AND T. THORNYCROFT.

STEERiNG GEAR FOR MOTOR BOATS.

APPLICATION HLED APR. 19, 1919.

1,362,450. Patented Dec. 14, 1920.

JOHN EDWARD rnonnronorr AND TQM rnonnrcnorr, on W S ENGLAND STEERING-GEAR FOR MOTOR BOATS.

Application filed April 19, 1919.

To all. to from it may concern Be it known that we, Sir JOHN EDWARD THoRNYoRorr and ToM Tr-ronnronorr, subjects of the King of Great Britain and Ireland, residing, respectively, at the city of Westminster, England, have invented Improvements in Steering-Gears for Motor- Boats, of which the following is a specification.

This invention has reference to improvements in steering gear for boats having screw propellers arranged in front of the rudders and it has for its object to provide steering gear specially suitable for high speed motor boats of shallow draft, whereby steering of such boats can be effected 1n an advantageous manner, the rudders supported in a simple and effectual way, passage of water through the stern of the boat prevented and the general construction and arrangement of the gear improved.

To this end in steering gear accordlng to the invention two rudders are used arranged to be operated from a single tiller and each mounted to turn upon the bracket of the corresponding forwardly arranged screw propeller. The tiller extends through an open ing in the stern or transom of the boat to the rear side of which each propeller bracket is secured and means are provided for preventing water passing through the said opening in the stern or transom of the boat. Each rudder is jointed to its corresponding bracket by hinges resembling ordinary door hinges, that is to say, butt hinges, with the result that the hinged connections can be kept down to quite a small diameter so that such connections will cause but very little water resistance at high speeds. Conveniently, the hinged connection compr ses a group of perforated lugs on the rudder meshing with a group of perforated lugs on the propeller shaft bracket at about the height of the bottom of the transom, similar intermeshing groups of lugs being arranged at the upper and lower end portions of the rudder, these lugs being connectedtogether by means of one or more vertical hinge plns passing axially through them.

The tiller is arranged midway between the twin rudders and is coupled at its after end by a pair of links to the upper portions of the rudders, at parts thereof near to their rear ends, the outer ends of the links being jointed to the rudders by pivotal connec tions.

Specification of Letters latent.

Patented Dec 14, 1920. Serial No. 291,293.

In the accompanying illustrative drawings, Figure 1 shows part ofa motor boat proyided with steering gear according to the invention, such steering gear being shown partly in side elevation and partly in longitudinal vertical section. Fig. 2 shows the boat with the steering gear in end elevation, Fig. 3 shows the steering gear partly in plan and partly in horizontal section.

a, a are the twin rudders and Z), 6 the twin propeller shaft brackets to which they are hinged at the after side thereof, each rudder, for this purpose, being provided with three groups of lugs a, a a intermeshing with three groups of lugs Z2, t 6 on the companion bracket Z), arranged as hereinbefore described, 0 being a hinge pin passing through and connecting the lugs together. (Z is a tiller arranged midway between the rudders. Its forward arm passes through the transom e of the boat and its after arm is coupled to the inner ends of a pair of transversely arranged links 7 the outer ends of which are coupled to the upper ends of the rudders a at parts thereof near their rear ends. In the example shown, the outer end of each link f enters a hole in the rudder and is pivotally connected to the rudder by a vertical hinge pin 9.

The forward arm of the tiller is provided at its front end with a quadrant 72, operated by a pinion z' and steering wheel 7', the vertical spindle for such pinion and wheel being carried in the ordinary way by a lower bracket m. The tiller is mounted to turn about a vertical axis in a transverse vertical plane forward of the vertical plane contain ing the axes of the rudder hinge pins 0, its fulcrum pin a being carried by a hollow bracket 0, through which the tiller extends and which bracket extends through and is fixed to the transom e. To facilitate adj ustment of the tiller fulcrum pin 12 to the correct position in a fore and aft direction, wood packing 39 may be arranged between a flange 0 on the forward end of the hollow bracket 0 and the front side of the transom e.

The pivoted portion of the tiller (Z may be arranged to form with the part of the hollow bracket 0 to which it is pivoted, a vertical cylindrical joint at 1" which is more or less fluid tight. To insure air and water being excluded from this joint, the hollow bracket 0 may be surrounded by a closely fitting vertical plate 8 having a horizontal tubular extension 8 of oval or other convenient shape, and the rear portion of the tiller may be provided with a circular or other shaped collar or part cl to which, and the said tubular extension 8', the end portions of a lose tube or bag 6 of flexible water and air tight material, for instance rubber, are secured, as by rope or wire, the arrangement being such as to exclude or prevent external air and water gaining access to the said joint at r and to the hollow bracket, but at the same time to allow of the free movement of the tiller.

Each of the propeller shaft brackets 5 may conveniently be fixed in position against the transom e by bolting a back plate 5 forming part thereof to the rear side of the transom e and to the upwardly extending portion a of an L shaped bracket a arranged at the front of the transom, the

lower horizontal portion of this bracket being fixed to the keel '0 of the boat '0. w, w are the bearings in the brackets b 5 for the rear end of the propeller shafts, the propeller, not shown, being in front of such bearings.

WVhat we claim is 1. In a motor boat, steering gear comprising two rudders mounted to turn on the respective propeller shaft brackets arranged at the after side of the corresponding propeller and a single tiller adapted to operate both rudders.

2. Steering gear according to claim 1, wherein the single tiller extends through the stern or transom of the boat.

3. Steering gear according to claim 1, wherein each rudder is jointed to its corresponding propeller shaft bracket by a hinge connection comprising a group of lugs on the rudder meshing with a group of lugs on the said bracket at about the height of the bottom of the transom, similar intermeshing. groups of lugs being arranged at the upper and lower end portions of the rudder, the lugs being connected together by pivotal means passing axially through them.

4. Steering gear according to claim 1, wherein the tiller is coupled at its after end by transverse links to the upper portions of the rudders.

5. In a motor boat having twin propellers, steering gear comprising two rudders mounted to turn on the propeller shaft brackets arranged at the after side of the propellers, a hollow bracket extending through and fixed to the stern or transom of the boat, a single tiller extending through and carried by said hollow bracket and means connecting said tiller to both rudders.

6. Steering gear according to claim 5, wherein the axis of the fulcrum pin of the tiller is arranged in a transverse vertical plane forward of the transverse plane containing the axes of the rudder hinge pins, substantially as described.

7. Steering gear according to claim 5, wherein the position of the hollow bracket can be adjusted in a fore and aft direction to adjust the position of the tiller fulcrum pin, substantially as described.

8. Steering gear according to claim 5, wherein the pivoted portion of the tiller is arranged to form with the hollow bracket through which the tiller extends, a vertical cylindrical more or less fluid tight joint, substantially as described.

9. Steering gear according to claim 5, wherein a loose tube or bag of flexible fluid tight material is secured to and around a part of the rear end portion of the tiller and to and around a fixed part closely surrounding the hollow bracket so as to prevent external air and water gaining access to the joint between the tiller and hollow bracket andto the hollow bracket, while at the same time allowing of free movement of the tiller, substantially as described.

10. Steering gear according to claim 5,'

wherein each propeller shaft bracket is provided with a plate whereby it is bolted to the rear side of the transom of the boat and to another plate at the front side of the transom, substantially as described.

11. Steering gear according to claim 5, wherein each propeller shaft bracket is provided with a plate whereby it is bolted to the rear side of the transom of the boat and to another plate at the front side of the transom, and each front plate forms an upwardly extending portion of an L shaped bracket the lower portion of which is fixed to the bottom of the boat, substantially as described.

Signed at London, England, this seventeenth da of March, 1919.

J OH EDWARD THORNYCROFT.

TOM THORNYCROFT. 

